ssbo/image load store woes

I'm implementing OIT /w linked lists and I have some really crazy artifacts. On some (majority) of the fragments i get exactly what is expect of this algorithm. On a few of them i'm getting some kind of flickering, which i suppose comes from bad list formation.

Now with option 1 it seems to work. With option 2 i get a guaranteed driver crash (on a Nvidia GTX460M, latest driver). I'm totally puzzled. They should be doing absolutelly the same thing.
I manually checked for a possible memory overflow and i am nowhere near the edge of the buffer. (using like 20% of Alha buffer memory)
In pass 2 i just walk the list .. nothing to write home about.

So my problems are:
- flickering on some pixels
- crash when writing like option 2

I suppose i miss something on the topic of synchronization (only thing that can be causing bad ordering AND apparently a deadlock). Any ideas? No code needed just a "it's this way it should be done" or "rtfm @lineX paragraphY" will suffice.